perf symbols: Add the build id cache to the vmlinux path

So that if the kernel DSO has a build id because record inserted it in
the perf.data build id table in the header, or a BUILD_ID event was
inserted in the stream, we first look at the build id cache
($HOME/.debug/).

If we find it there, try to use it, allowing offline annotation in
addition to 'perf report'.

Reported-by: Stephane Eranian <eranian@google.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 24 insertions, 5 deletions

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index aaa51ba147df..7fd6b151feb5 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1695,9 +1695,20 @@ int dso__load_vmlinux_path(struct dso *self, struct map *map,
                            symbol_filter_t filter)
 {
         int i, err = 0;
+        char *filename;
 
         pr_debug("Looking at the vmlinux_path (%d entries long)\n",
-                 vmlinux_path__nr_entries);
+                 vmlinux_path__nr_entries + 1);
+
+        filename = dso__build_id_filename(self, NULL, 0);
+        if (filename != NULL) {
+                err = dso__load_vmlinux(self, map, filename, filter);
+                if (err > 0) {
+                        dso__set_long_name(self, filename);
+                        goto out;
+                }
+                free(filename);
+        }
 
         for (i = 0; i < vmlinux_path__nr_entries; ++i) {
                 err = dso__load_vmlinux(self, map, vmlinux_path[i], filter);
@@ -1706,7 +1717,7 @@ int dso__load_vmlinux_path(struct dso *self, struct map *map,
                         break;
                 }
         }
-
+out:
         return err;
 }
 
@@ -2102,13 +2113,21 @@ out_fail:
         return -1;
 }
 
-size_t vmlinux_path__fprintf(FILE *fp)
+size_t machine__fprintf_vmlinux_path(struct machine *self, FILE *fp)
 {
         int i;
         size_t printed = 0;
+        struct dso *kdso = self->vmlinux_maps[MAP__FUNCTION]->dso;
+
+        if (kdso->has_build_id) {
+                char filename[PATH_MAX];
+                if (dso__build_id_filename(kdso, filename, sizeof(filename)))
+                        printed += fprintf(fp, "[0] %s\n", filename);
+        }
 
         for (i = 0; i < vmlinux_path__nr_entries; ++i)
-                printed += fprintf(fp, "[%d] %s\n", i, vmlinux_path[i]);
+                printed += fprintf(fp, "[%d] %s\n",
+                                   i + kdso->has_build_id, vmlinux_path[i]);
 
         return printed;
 }
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 5d25b5eb1456..5e02d2c17154 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -216,6 +216,6 @@ int machines__create_guest_kernel_maps(struct rb_root *self);
 int symbol__init(void);
 bool symbol_type__is_a(char symbol_type, enum map_type map_type);
 
-size_t vmlinux_path__fprintf(FILE *fp);
+size_t machine__fprintf_vmlinux_path(struct machine *self, FILE *fp);
 
 #endif /* __PERF_SYMBOL */